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"This fabric and rubber mask was stand issue for every doughboy. The hose connected to a canister that held an air filter, and it was designed to protect the wearer against such toxic agents as chlorine, phosgene, and mustard gas, which were deployed by both sides in what has been called the "chemists' war." Poison gas killed 90,000 soldiers, prompting the Geneva Protocol of 1925, among the first international treaties banning chemical weapons in war."
- Smithsonian Magazine